Treadbase lifting mechanism of a treadmill

ABSTRACT

A treadbase lifting mechanism is disclosed to include a framework with a treadbase above on it, a plank balanced on a fulcrum at the framework having one end pivoted to the an end of the treadbase, a driving mechanism, a sprocket pivotally mounted in the framework, and a chain meshed with the sprocket and connected between the driving mechanism and the other end of the plank for driving by the driving mechanism to turn the plank and to further lift the treadbase to the desired tilted position.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to exercising apparatus and more particularly to a treadbase lifting mechanism of a treadmill.

2. Description of the Related Art

A treadmill has a treadbase upon which the user treads. The treadbase can be adjusted to the desired tilted position. FIGS. 1 and 2 show a treadbase lifting mechanism according to the prior art design, which was also invented by the present inventor. According to this design, the treadbase lifting mechanism comprises a motor 1, a rack 2, and an arched link 3. The rack 2 is meshed with the pinion at the output shaft of the motor 1. The arched link 3 is coupled between the rack 2 and one end of the treadbase of the treadmill. Rotating the motor 1 causes the rack 2 to move the arched link 3 and to further lift or lower the treadbase of the treadmill. This design allows adjustment of the treadbase to the desired tilted position. However, because the driving force of the motor is not directly transmitted to the treadbase but through the arched link, the horizontal push/pull force provided by the driving mechanism is not the vertical push/pull force required for adjusting the tilting angle of the treadbase. Therefore, the driving mechanism must have a strong output force to move the rack so that the arched link can provide sufficient vertical component of force to lift the treadbase. Due to this limitation, this treadbase lifting mechanism requires much installation space and wears quickly with use.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a treadbase lifting mechanism for treadmill, which saves the output power of the driving motor and reduces the size of the treadmill.

To achieve this and other objects of the present invention, the treadbase lifting mechanism comprises a framework placed on a flat surface to support a treadbase; a driving mechanism mounted in the framework, the driving mechanism having a movable end adapted to provide a reciprocating driving force; a plank pivotally mounted on a fulcrum at the framework and balanced on the fulcrum, the plank having a rear end pivoted to the an end of the treadbase; a rotary member pivotally mounted in the framework in front of the movable end of the driving mechanism; and a flexible connecting member extending over the rotary member and connected between the front end of the plank and the movable end of the driving mechanism for driving by the movable end of the driving mechanism to turn the plank up and down on the fulcrum.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a prior art design.

FIG. 2 is a side view of the prior art design shown in FIG. 1.

FIG. 3. is a side view of the present invention, showing the treadbase set in horizontal.

FIG. 4 corresponds to FIG. 3, showing the treadbase set in a tilted position.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 3, a treadbase lifting mechanism in accordance with the present invention is shown comprising a framework 10, a driving mechanism 20, a rack 23, a plank 40, a rotary member 50, and a flexible connecting member 60.

The framework 10 can be placed on a flat surface, having a treadbase 11 above on it.

The driving mechanism 20 is mounted in the framework 10 and adapted to provide a reciprocating driving force. According to this embodiment, the driving mechanism 20 is comprised of a reversible motor 21 mounted in the framework 10, a drive gear 22 fixedly mounted on the output shaft of the motor 21, and a rack 23 longitudinally slidably mounted in the framework 10 and meshed with the drive gear 22. Starting the motor 21 to rotate the drive gear 22 forwards/backwards, the rack 23 is moved longitudinally forwards/backwards in the framework 10. Alternatively, the driving mechanism 20 can be formed of a worm and a worm gear.

The plank 40 is pivoted to the framework 10 and balanced on the fulcrum at the pivoted point, having one end, namely, the rear end pivoted to the an end (the front end) of the treadbase 11.

The rotary member 50 is pivotally mounted in the framework 10 in front of the rack 23. The rotary member 50 can be a roll or gear wheel. According to this embodiment, the rotary member 50 is a sprocket.

The flexible connecting member 60 has one end connected to the movable end of the driving mechanism, i.e., connected to one end of the rack 23, and the other end extending over the rotary member 50 and connected to the other end, namely, the front end of the plank 40. Therefore, the flexible connecting member 60 changes the horizontal acting force produced by the motor 20 into a vertical acting force and transmits this vertical acting force to the front end of the plank 40. The flexible connecting member 60 can be a wire, cable, or chain. According to this embodiment, the flexible connecting member 60 is a chain meshed with the sprocket 50 and connected between the front end of the rack 23 and the front end of the plank 40.

FIG. 3 shows the treadbase 11 set in horizontal. At this time, the rack 23 is disposed adjacent to the rotary member 50, the plank 40 is held in a tilted position with the front end received inside the framework 10 and the rear end spaced above the framework 10.

When wishing to tilt the treadbase 11, start the motor 21 to rotate the drive gear 22 and to further move the rack 23 horizontally backwards, thereby increasing the distance between the rotary member 50 and the rack 23 and driving the flexible connecting member 60 to pull the front end of the plank 40 downwards. When pulling the front end of the plank 40 downwards, the front end of the plank 40 is turned upwards to lift the front end of the treadbase 11, and therefore the treadbase 11 is tilted to the desired tilted position. Because the flexible connecting member 60 is used and driven to change the horizontal acting force produced by the motor 20 into a vertical acting force and to transmit this vertical acting force to the front end of the plank 40, no component or dispersion of force will be produced during the operation of the present invention, i.e., the invention prevents a loss of driving force when tilting the treadbase.

Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. 

1. A treadbase lifting mechanism comprising: a framework; a treadbase above said framework; a driving mechanism mounted in said framework, said driving mechanism having a movable end adapted to provide a reciprocating driving force; a plank pivotally mounted on a fulcrum at said framework and balanced on said fulcrum, said plank having a rear end pivoted to an end of said treadbase; a rotary member pivotally mounted in said framework in front of the movable end of said driving mechanism; and a flexible connecting member extending over said rotary member and connected between the front end of said plank and the movable end of said driving mechanism for driving by said movable end of said driving mechanism to turn said plank up and down on said fulcrum.
 2. The treadbase lifting mechanism as claimed in claim 1, wherein said rotary member is a gear wheel.
 3. The treadbase lifting mechanism as claimed in claim 2, wherein said flexible connecting member is a chain.
 4. The treadbase lifting mechanism as claimed in claim 1, wherein said rotary member is a roll.
 5. The treadbase lifting mechanism as claimed in claim 4, wherein said flexible connecting member is a cable. 